MSE: Warn when keyframe after track_buffer is significantly in future

media/filters/source_buffer_stream_unittest.cc

Index: media/filters/source_buffer_stream_unittest.cc
diff --git a/media/filters/source_buffer_stream_unittest.cc b/media/filters/source_buffer_stream_unittest.cc
index 3d03ccd16867f6c662ee0fa28e3e2e31fcf045bb..4ea3329ea840566394eb55c7a9b3b03e268a0b82 100644
--- a/media/filters/source_buffer_stream_unittest.cc
+++ b/media/filters/source_buffer_stream_unittest.cc
@@ -4285,6 +4285,64 @@ TEST_F(SourceBufferStreamTest, ConfigChange_ReSeek) {
   CheckVideoConfig(new_config);
 }
 
+TEST_F(SourceBufferStreamTest,
+       TrackBuffer_WithDelayUntilNextKeyframeInOverlap) {
+  NewSegmentAppend("0K 10 20 30 40");
+
+  // Read the first 4 buffers, so next buffer is at time 40.
+  Seek(0);
+  CheckExpectedRangesByTimestamp("{ [0,50) }");
+  CheckExpectedBuffers("0K 10 20 30");
+
+  // Overlap-append, populating track buffer with timestamp 40 from original
+  // append. Confirm there could be a large jump in time until the next key
+  // frame after exhausting the track buffer.
+  NewSegmentAppend(
+      "31K 41 51 61 71 81 91 101 111 121 "
+      "131K 141");
+  CheckExpectedRangesByTimestamp("{ [0,151) }");
+  // Confirm the large jump. If this test is changed, update
+  // TrackBufferExhaustion_ImmediateNewTrackBuffer accordingly.
+  CheckExpectedBuffers("40 131K 141");
+  CheckNoNextBuffer();
+}
+
+TEST_F(SourceBufferStreamTest,
+       TrackBuffer_ExhaustionAndImmediateNewTrackBuffer) {
+  NewSegmentAppend("0K 10 20 30 40");
+
+  // Read the first 4 buffers, so next buffer is at time 40.
+  Seek(0);
+  CheckExpectedRangesByTimestamp("{ [0,50) }");
+  CheckExpectedBuffers("0K 10 20 30");
+
+  // Overlap-append
+  NewSegmentAppend(
+      "31K 41 51 61 71 81 91 101 111 121 "
+      "131K 141");
+  CheckExpectedRangesByTimestamp("{ [0,151) }");
+
+  // Exhaust the track buffer, but don't read any of the overlapping append yet.
+  CheckExpectedBuffers("40");
+
+  // Selected range's next buffer is now the 131K buffer from the overlapping
+  // append. (See TrackBuffer_WithDelayUntilNextKeyframeInOverlap for
+  // confirmation.)
+  // Do another overlap-append to immediately create another track buffer and
+  // verify.
+  NewSegmentAppend("22K 32 42 52 62 72 82 92 102 112 122K 132 142 152K 162");
+  CheckExpectedRangesByTimestamp("{ [0,172) }");
+
+  //**********
+  // BIG TODO: The following outputs to MediaLog a message understating the
+  // actual gap. Actual gap is time 40->131K==91ms. Log shows 11ms==141->152K.
+  // Fix the implementation and perhaps verify the log with a MockMediaLog?
+  //**********
+
+  CheckExpectedBuffers("131K 141 152K 162");
+  CheckNoNextBuffer();
+}
+
 // TODO(vrk): Add unit tests where keyframes are unaligned between streams.
 // (crbug.com/133557)